LED Display: http://www.sparkfun.com/commerce/product_info.php?products_id=9230
Can I simultaneously control two of the above listed displays with a Arduino Pro Mini?
I see there are 2 rx, 2 tx and 2 gnd on the board, so after I program it I would like each display to always be on and I would like the ability to transmit a different signal to each one simultaneously.
Those pairs of Rx and Tx connections are actual the same signals brought out to different pins for convenience: there's only one hardware UART.
Since your clock won't be very busy, you can use the SoftwareSerial library to send the commands to the two different displays using other digital pins. I recommend putting both displays on software serial pins, so you can leave the hardware serial port connected to the PC all the time for ease of development.
Awesome, thanks for the information. Software serial will be very useful for this project.